Seaweeds of the South African South Coast

 

 

 

 

 

 

 

 

 

 

 

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Order Ceramiales

Family Rhodomelaceae

Dictyomenia stephensonii Papenfuss 1947: 4-5, pl. 1: fig. 4; pl. 2: figs. 12, 13 ('Dictymenia')

Plants dark maroon-red, erect, up to 25 cm tall, with spirally twisted, dentate axes; attachment by stoloniferous axes; flattened complanate uprights borne on short (-1.5 cm) stipe, 2-5 mm wide, with tooth-like determinate laterals up to about 3 mm long, apices of uprights twisted but not inrolled. Structure comprising central axial filament and 6 pericentral cells, lateral pericentral cells dividing to form wings of axes, cortication of a single layer of small cells; midrib distinct in lower parts of thallus; axial filaments visible when axes held to the light; determinate laterals arising from every fourth segment, alternately branched, angled towards apices. Reproductive structures not seen.

Collections, ecology and regional distribution

Recorded from the Mbashe River Mouth (Dwesa/Cwebe, Transkei) to Cape Vidal area. (44-56). Found in the sublittoral fringe and in pools, often in shaded locations.

World distribution: South African endemic.

Type locality: Port Shepstone, Kwazulu-Natal (Silva et al. 1996).

 

Dictyomenia stephensoniae, habit (pressed specimen).

Dictyomenia stephensoniae, young pressed specimen.

Dictyomenia stephensoniae, detail of frond showing midrib, determinate laterals (teeth)

Dictyomenia stephensoniae, cross section through midrib of mature frond (re-hydrated pressed specimen).

Dictyomenia stephensoniae, xs showing cortical cells and outer medulla (re-hydrated pressed specimen).

 

References Dictyomenia

Papenfuss, G.F. 1947. New marine algae from South Africa; I. University of California Publications in Botany 23: 1-15.

Silva, P.C., Basson, P.W. & Moe, R.L. 1996. Catalogue of the benthic marine algae of the Indian Ocean. University of California Publications in Botany 79: 1-1259.

 

Cite this record as:

Anderson RJ, Stegenga H, Bolton JJ. 2016. Seaweeds of the South African South Coast.
World Wide Web electronic publication, University of Cape Town, http://southafrseaweeds.uct.ac.za; Accessed on 19 December 2024.